Bacterial and viral dynamics during a mass coral spawning period on the Great Barrier Reef

Abstract

Bacterial and virus-like particle (VLP) abundances and physical and chemical parameters were measured in reef water and sediments over a 10 d period, coinciding with mass coral spawning at Heron Island, Great Barrier Reef. Bacterial abundances in reef water increased 2-fold after spawning and remained elevated for 3 d, before declining to below pre-spawning values. Reef water VLP abundances were also elevated 2 d after spawning; however, VLP abundances exhibited a general decline over the study. Dissolved oxygen (DO) and total nitrogen (TN) concentrations appeared to be dominant factors driving reef water bacterial and VLP dynamics. Sediment bacterial and VLP abundances exceeded those in the water column by up to 3 orders of magnitude and exhibited strong positive correlations for all investigated sediment depths. While short-lived peaks in bacterial and VLP abundances within sediments lagged behind water column trends by 2 d, reef water total phosphorus (TP) concentrations were strongly correlated with sediment bacterial and VLP abundances. Shifts in bacterial and VLP abundances in reef water and sediments during the study corresponded with 2 distinct periods: one prior to, and one after the first night of intense spawning. Scavenging by sedimenting coral spawn material is proposed as a direct mechanism contributing to these shifts, by removing bacteria and VLPs from the water column. The input of organic matter and associated nutrients from mass coral spawning, and the immediate and strongly correlated responses of bacteria and VLPs, indicate that viruses are important players in nutrient cycling processes in coral reefs.

Intergenerational Transfer of Specific Bacteria in Corals and Possible Implications for Offspring Fitness

“…A previous study reported that the abundance of Roseobacter increased in three coral species after a coral mass spawning event on Ningaloo Reef [4], and clone libraries retrieved Reef, the bacterial abundance in the water column increased twofold and returned to pre-spawning levels after 3 days [18].…”

Uncoupled viral and bacterial distributions in coral reef waters of Tuamotu Archipelago (French Polynesia)

“…Variability amongst coral reef bacterial communities has been investigated at a variety of spatial and temporal scales (Moriarty, 1979;Moriarty et al, 1985;Paul et al, 1986;Hoppe et al, 1988;Gast et al, 1998) and significant variations in abundance, activity and composition have been observed over small spatial and temporal scales (Paul et al, 1986;Gast et al, 1998;van Duyl and Gast, 2001;Frias-Lopez et al, 2002;Rohwer et al, 2002). The role of virioplankton in coral reef systems remain relatively unexplored (Seymour et al, 2005;Mari et al, 2007;Dinsdale et al, 2008), as well as the presence and the roles of viruses associated with healthy and diseased corals which warrant further investigation (Weil et al, 2006;Patten et al, 2008). Nothing is known on the mode of viral infections and the life strategy of virioplankton in coral reef systems.…”

Deciphering the genomic toolkit underlying animal-bacteria interactions – insights through the demosponge Amphimedon queenslandica

“…The healthy and unhealthy A. queenslandica bacteria treatments were administered at a density of roughly 2.8 x 10 4 cells/ml. By comparison, the seawater around Heron Island where the sponges were collected, contains an estimated 0.5-1.0 x 10 6 cells/ml (Patten, et al 2008). Given that the core components of the A. queenslandica bacterial community are rarely detected in seawater, the treatments would have exposed the sponges to a much higher load of symbiont bacteria than they would typically encounter.…”